There is no hackery require to make IPv4 work in LTE. LTE supports IPv4, IPv6, and IPv4v6 bearers all the same... its just an option from the core perspective, handset / chipset makers like to limit the options to keep cost and variability down.
My understanding (admittedly second hand, so perhaps the engineer explaining it to me was mistaken) was that LTE was IPv6 and that IPv4 was implemented on the radio side essentially as a 4in6 tunnel with a very very short-term DHCP lease for the v4 address.
Nope, it does not work this way. There are tunnels for mobility, and it is possible that IPv4 user plane packet get carried in IPv6 GTP packets but that is the same case for IPv6 user plane also being in IPv6 GTP packets.... but LTE generally does not use any DHCP to the user.
Key point: LTE does not imply any mandatory IPv6 networks infrastructure or services, but it does work with IPv6 and should be deployed with IPv6.
Cameron (who works in mobile, everyday)
OK... Thanks for the clarification. So did the other guy who gave me the other story. I won't pretend to be a mobile expert. Owen